1. Field of the Invention
The invention relates to a heat column and a heat dissipating apparatus contained therein, and more particularly to a flat heat column with reduced airflow resistance, and a heat dissipating apparatus containing the flat heat column.
2. Description of the Related Art
As efficacy of electronic products continuous increased, heat dissipating apparatuses play a critical role in electronic apparatuses. Poor heat dissipation can lead to damage or failure for the entire electronic products.
Heat dissipating apparatuses are important in microelectronic elements, (e.g. integrated circuit, IC). Due to the increase of integration and advancement of packaging technology, integrated circuit area is increasingly reduced and the heat per unit area is thus increased. Thus, high efficacy heat dissipating apparatuses are under continuous active development by electronic industry.
Heat pipes are widely used in electronic products because they are capable of dissipating a great amount of heat from a heat source through a small contact area without requiring additional power. In general, heat pipes are used with heat sink and a fan so that heat generated from the heat source can be transferred to the heat pipe, and then rapidly dissipated through the fins of the heat sink. Also, the fan provides airflows for dissipating the heat by heat convection.
FIG. 1A is a schematic view of a conventional heat dissipating module. A conventional heat-dissipating module 1 is constituted by a cylindrical heat pipe 11, a heat sink 12 and an axial fan 13 located at the side of the heat sink 12 for lateral blowing airflows to dissipate heat from a heat-generating electronic apparatus (hereafter the heat source, not shown). When the cylindrical heat pipe 11 contacts the underlying heat source, the work fluid at the vapor end of the cylindrical heat pipe 11 is transformed to vapor by absorbing heat. The vapor is transported to wick structures at the cooling end by pressure. The vaporized work fluid is transformed to liquid by releasing the latent heat therein. The liquid work fluid is then transported back to the vapor end by wick structures disposed at the inner wall of the cylindrical heat pipe 11. The heat at the cooling end is conducted to the heat sink 12 via heat conduction and airflow generated by the fan 13 exhausts the heat to the environment via heat convection.
FIG. 1B is a schematic view of the fluid field of the heat dissipating module. In this dissipating process of heat dissipating module, airflow “A” generated by the fan 13 is dispersed when passing the cylindrical heat pipe 11, causing a large stagnant zone “B” after the cylindrical heat pipe 11 is generated. Thus, no heat convection occurs in the stagnant zone B, which reduces the entire efficiency of the heat dissipating module. In addition, the heat sink 12, formed by pressing and engaging, are typically chosen to match the cylindrical heat pipe 11. The manufacturing cost of this type of heat sink 12 is, however, higher.